Relay



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RELAY Filed Feb. 6, 1941 ATTORNEY Patented Aug. 11, 1942 RELAY Robert Vradenburgh, Yonkers, N. Y., assigner to Ward Leonard Electric Company, a corporation of New York Application February 6, 1941, Serial No. 377,678

(Cl. 20D-87) through the base and engage the upwardly ex- 7 Claims.

This invention relates to relays adapted for use by either alternating or direct current and adapted for the control of one or more circuits for various purposes, such as the control of electric heaters, signals. lights, pumps, compressors and the like. The relay is herein shown and described as of a single pole type, although various features of the invention are adapted for use in multi-pole relays.

One object of the invention is to produce a relay of compact construction occupying small space and comprising a small number of parts which may be produced at low cost and readily assembled and be durable under long continued operation. Another object is to impose pressure on the contacts in both the attracted and unattracted positions of the armature by a single spring. Another object is to permit the use of a compression spring instead of a tension spring and thereby avoid the possibility of the parts becoming free and causing possible damage by accidental contact of the free part or parts. By using a compression spring suitably confined, the spring, even if broken, will always function to exert some pressure. Another object is to impose a wiping contact action on the contacts after their closure so as to be self-cleaning and insure a good electrical contact. Another object is to provide a large area of contact between the movable armature and the xed part of the magnetic circuit and provide low reluctance in the bearing support when the armature is in the open circuit position and thereby reduce the ratio of open to closed impedance. Another object is to provide a structure which will retain the parts in their proper relative positions at al1 times and not-be subject to displacement by shocks or jars. Other objects and advantages will be understood from the following description and accompanying drawing which illustrate one embodiment of the invention.

Fig. 1 is a front elevation; Fig. 2 is a side View partly in section; Fig. 3 is a side view partly in section showing the parts in an intermediate position; and Fig'. 4 is an end view.

The parts are shown mounted on a base I of insulating material. The controlling coil 2 is provided with a central core 3 having a shading coil or closed loop I at its outer end, one portion of the loop passing through a slot in the outer tending leg of the magnet frame, the upper screw entering the inner end of the core 3 and serving to hold it rmly against the upward extension of the magnet frame. The terminals of the coil are connected to binding posts 'l which are xed to the base and are positioned at opposite sides of the coil. They are provided with screws 1a at the top of the posts and with washers 1b with outwardly turned edges broken away at a portion hereof for convenient connection of leads there- The movable armature is formed of a strip of ironor steel having a leg 8 extending upwardly and passing over the outer end of the core of the magnet. this leg being bent almost at rightangles to the other leg 8a of the amature which extends inwardly and along the outwardly extendingleg of the magnet frame. The armature is pivotally mounted upon the outer end of the magnet frame.

The contact iinger is also composed of a strip of metal which may be of non-magnetic material or of iron or steel and is in the form of two legs 9 andI 9a bent to an angle of almost 90 with reference to each other. The leg S extends over and beyond lthe leg 8 of the movable .armature and carries the movable contact 9b at its end. The leg 9a extends inwardly and over the outer surface of the leg 8a of the movable armature. The finger is provided with punched out metal extensions 9c which are bent over to clamp the end of the flexible lead I0 and to hold it in fixed connection therewith. The end of the lead is soldered to the finger at one of the clamps to maintain good electrical connection. The lead I0 is connected to its binding post I I fixed to the base for convenient connection to an outside lead. The inner end of the contact nger near the base is provided with inwardly bent ears 9d at opposite sides which extend toward the coil and loosely embrace the inner .end of the movable armature and a portion of the magnet frame to serve as guides and to assist in maintaining the parts in proper relationship. 'I'he upper and outer end of the movable armature is also provided with ears 8b which are bent to extend outwardly and loosely embrace the upper end of the contact linger for the purpose of maintaining these parts in proper relation to each other.

A pin I2 is iixed at its inner end, by riveting or otherwise, to the outwardly extending leg of the magnet frame 5 and extends downwardly andfreely through a slot 8c in the movable armature and through an opening 9e in the leg 9a of the contact finger. A compression spring I3 surrounds this pin and is seated at its inner end against a cup washer. Il and retained in place at its outer end by a cup washer Ila. 'I'he outer end of the pin I2 is grooved to receive a. U-shaped retaining element I5 which mayreadily be slipped into place for retaining lthe washer Ila in place and for imposing suitable pressure upon the spring. Within the spring is a loosely positioned sleeve I6 which is of slightly less length than the distance betweenthe cup washers I4 and Ila when the amature is in its attracted position, this sleeve serving to prevent undue side-wise movement of the parts about the pin in uses where the relay might be sub- Jected to extreme shocks or jars. Such possible side-wise movement causes one side of the washer I4 to be forced outwardly and engage the inner end of the sleeve and thereby prevents any further pronounced side-wise movement of the upper end of the movable armature and contact finger.

The leg 8a of the armature is provided with a pair of outwardly forced projections I1 which are positioned outwardly with relation to the vpin I2 and located one at each side thereof,

as shown in Figs. 1 and 2. These serve as pivot points for the contact finger except when the latter is in its fully attracted position. The relay is shown provided with an inner fixed contact I8 and an outer fixed contact I9 adapted to be engaged by the contact of the linger respectively when in its attracted and unattracted positions. The inner fixed contact is supported by a strip of metal Ia which extends side-wise and is then bent to extend towards the base and then again bent at the base to extend under the fixed binding post lab. The outer fixed contact is supported by a strip of metal I9a which extends side-wise and then bent to extend toward the base and again bent at the base to extend under the fixed binding post ISb. It is obvious that a circuit connected to the binding posts Il and IBb will be closed when the relay is in its attracted position and that a circuit connected to the binding posts Il and Iilb will be closed when the relay is in its unattracted position. The relay may be connected to secure various circuit controls according to the particularr requirements.

Fig. 2 shows the parts in theiry relative positions when the relay is deenergized, the movable contact then engaging the outer fixed contact. In this position the spring I3, by exerting its pressure against the leg 9a of the contact finger and in turn against the projections I1, holds the armature outwardly; and also by reason of the spring pressure being exerted on the inner portion of the leg 9a of the contact finger at its inner portion with reference to the projections I1, it forces the leg 9 of the contact finger outwardly and thereby forces the movable contact 9b with adequate pressure against the fixed contact I9. When current passes through the coil of the relay equal to `or exceeding the pick-up value, the armature 8 will be attracted toward the outer end of the magnet core and will turn about the outer end of the xed magnet frame 5 as a pivot. In its initial movement the armature moves independently of the contact nger until the inner end of the armature swings downwardly to engage the inner end of the contact finger. It then forces the contact finger to move with the armature and thereby causes the movable contact to engage the fixed contact II as shown -by the full line position of the parts in Fig. 3. The continued movement oi' the armature from this position to the end of the magnet corethencausestheinnerendofthearmature to force the contact finger downwardly and to take a position below the projection I1, as indicated by the dotted lines in Fig. 3. In this latter movement, the movable contact is moved downwardly, giving a wiping contact in this portion of the movement. This, of course, serves to maintain the contacts clean and insures a good electrical contact during long continued use. Although the relay may be mounted in any position, it is usually mounted in a vertical positionasshowninthedrawingandanyarcthat may form tends to occur at or near the upper portion of the contact area. Consequently the downward movement of the contact in its wiping action just described, moves the contact away from the arcing region andI thereby causes the contacts to engage an area which has been least affected by the arcing. Thus the direction of movement in this wiping contact action is of special advantage when the relay is mounted in a vertical position.

When the coil of the relay is deenergized or its current reduced suiiiciently to release the armature, the spring I8 will act to first move leg 9a of the contact finger toward the armature and against the projections I1 and in such action causes the movable contact to wipe against the contact Il before separating from that contact. The spring then moves both the contact nnger and armature about the outer end of the magnet frame, thereby separating the movable contact from the fixed contact Il and moving it into engagement with the fixed contact I9. During this action the leg la of the contact finger engages the inner end of the leg 8a and likewise the projections II. After engagement with the fixed contact I9, the pressure of the spring against the leg la of the contact finger and through it against the projections I1, forces the leg 8a closely against the outwardly extending arm of the magnet frame. This nal movement permits the leg 9a of the contact finger to move somewhat towards the projecting arm of the magnet frame and thereby results in a wiping action of the movable contact against the fixed contact I9 after engagement of these contacts. When the armature is again attracted, the reverse action takes place.

It is evident that the relay is of compact construction and made of parts which may be easily and economically manufactured and readily assembled and disassembled. The single spring serves to impose pressure of the movable contact against the fixed contacts in both the attracted and unattracted positions of the relay and thereby avoids the use of a flexible contact carrying arm usually associated with relays having a single spring. In this case the term spring is interpreted as that type constructed with spring wire suitably coiled on a mandrel as distinguished from a hat or leaf spring. The contacts may be silver faced if desired. The wiping action of the contacts render them self-cleaning and insures good contact in bothv the attracted and unattracted positions of the relay. In case the relay is used for closing a circuit in the attracted position only, the outer fixed contact I9 and its supporting strip may be omitted, as the outwardly extending end of the magnet frame will serve as a stop for the outward movement of the parts. When the contact finger is made oi' magnetic material it serves to increase the contact pressure in the attracted position of the relay and such increased pressure may be desirable in some cases.

Although a particular embodiment of this invention has been described, it will be understood that various modiiications may be made without departing from the scope of the invention.

I claim:

1. A relay comprising a coil. a magnet frame in the form of a ilat strip extending along one side and one end of the coil, an armature in the form of a iiat strip extending over the coil and bent to extend over the outside of said magnet frame strip and pivotally mounted on the end thereof, a contact finger extending ,over and engaging both portions of said armature, a coinpression spring forv forcing portions of said iinger and armature toward said magnet frame strip, and a iixed contact adapted to be engaged by said contact iinger.

2. A relay comprising a coil, a magnet frame in the form of a at strip extending along one side and one end of the coil, an armature in the form of a ilat strip extending over the coil and bent to extend over the outside of said magnet frame strip and pivotally mounted on the end thereof, a contact ringer extending over and engaging both portions of said amature, a pin xed to said magnet frame strip and extending outwardly freely through said contact iinger and through said portion of the armature strip extendingover the magnet frame strip, a compression spring mounted on said pin and restrained at the outer end thereof and exerting pressure against portions of said contact linger and armature toward said magnet frame strip, and a iixed contact adapted to be engaged by said contact linger.

3. A relay comprising a coil, a magnet frame in the form of a ilat strip extending along one side and one end of the coil, an armature in the form of a ilat strip extending over the coil and bent to extend over the outside of said magnet frame strip and pivotally mounted on the end thereof, a contact finger extending over and engaging both portions of said amature, a pin nxed to said magnet frame strip and extending outwardly freely through said contact finger and through said portion of the armature strip extending over the magnet frame strip. a compression spring mounted on said pin and restrained at the outer end thereof and exerting pressure against portions of said contact linger and armature toward said magnet frame strip, a iixed contact adapted to be engaged by said contact finger and means for limiting sidewise movement of the contact nger and amature.

4. A relay comprising a coil. a magnet frame intheiorm oiailatstrlpextendingalong one sideandoneendofthecoihanarmatureinthc form of a iiat strip extending over the coil and bent to. extend over the outside of said magnet thereof, a contact linger extending over and engaging both portions of said armature, a compression spring for forcing portions of said linger and armature toward said magnet frame strip, said contact finger having guiding extensions embracing the edges oi said armature and magnet frame strip, and said armature having guiding extensions embracing the edges of the contact strip, and a fixed contact adapted to be engaged by said contact ilnger.

5. A relay comprising a coil, a magnet frame intheform ofaiiatstripextendingalongone side and one end of the coil, an armature in the form of a ilat strip extending over the coil and bent toextend over the outside of said magnet frame strip and pivotally moimted on the end thereof, a contact linger extending over and engaglng both portions of said armature, said armature portion extending over the outside of the magnet frame strip having a projection for forming a pivot :for the contact finger, a compression spring for forcing portions of said contact nger and armature toward said magnet frame i'rarnestripamlpivotallymuruntedontheend strip, and a fixed contact adaptedto be engaged by said contact iinger.

6. A relay comprising a coil, a. magnet frame in the form of a at strip extending outwardly along one side and one end of the coil, an armature in the form of a. fiat strip extending over the coil and bent to extend inwardly over the outside of said magnet frame strip and pivotally mounted on the end thereof, a contact iinger extending over and engaging both portions of said armature, said inwardly extending portion of said armature having a projection for forming a pivot for the contact linger, a compression spring for forcing portions of said contact iinger and armature toward said magnet frame strip, said spring being positioned to exert its force on a portion of said contact finger extending between said projection and the inner end of said armature strip, and a iixed contact adapted to be engaged by said contact linger.

7. A relay comprising a coil, a magnet frame in the form of a ilat strip extending along one side and one end of the coil, an armature in the form of a'fiat strip extending over the coil and bent to extend over the outside of said magnet frame strip and pivotally mounted on the end thereof, a contact iinger extending over and engaging both portions of said armature, a pin iixed to said magnet frame strip and extending Voutwardly freely through said contact linger and through said portion of the amature strip extending over the magnet frame strip, a compression spring mounted on said pin and restrained at the outer end thereof and exerting pressure against portions of said contact iinger and armature toward said magnet framestrip, a xed contact adapted to be engaged by said contact iinger, and a sleeve surroundingsaid pin for limiting sidewise movement of the contact iinger and armature.

ROBERT VRADENBURGH. 

